The dancing, delicate foliage of early meadow-rue (Thalictrum dioicum) makes this one of my favorite native plants for shady gardens. It is easy to grow, not very tall, and spreads gently, making it the ideal candidate for a ground cover. Additionally, it starts into growth early. A hot, dry summer can scorch the pretty leaves, but it will usually make fresh new growth in the fall. The flowers, male and female on separate plants, are small and tremble in the breeze. They are not very showy, which is actually a good feature in a ground cover, as it allows your starring flowers to shine without competition.
Early meadow-rue persists in woodlots which are over-run with deer and where all the tasty liliaceous flowers have long since disappeared, so it must be at least partially resistant to deer. It is in the family Ranunculacea, or buttercup family, which has some famously toxic members: buttercups themselves, monkshoods, and others.
Early meadow-rue thrives on heavy soil and its height will vary considerable with the moisture supply in the ground. It can be about 16 inches high in a moist swale in the woods. In most gardens it will grow no more than 10 inches high.
The showier tall meadow-rue is the better known native, perhaps because it fits better with our idea of what a meadow-rue should be. The non-native garden meadow-rues are tallish plants grown for their flowers. I think you will like pretty little early meadow-rue when you get to know it.
With this scarily early spring galloping along, I had better get to the discussion on native ground covers I promised.
There is one little native plant that makes a neat evergreen carpet, has pretty yellow flowers, and is not restricted to acid soils. I wish I could whole-heartily recommend it. On its own merits, I could readily recommend our little barren strawberry (Waldsteinia fragarioides) as a ground cover for light shade. However, it is very difficult to source. Every generalist nursery or garden centre that I have ever seen offering barren strawberry has the European look-alike, not our little native. What difference it would make to the ecosystem of your garden, I don’t know. Experience has shown that there are differences, and we often find out what they are only after the non-native has proven invasive, at worst, or, at best, has disappointed in some role in providing for birds or pollinators that the native species could have provided.
If you can find a native plant specialty nursery that offers the native barren strawberry, by all means try it out as a little evergreen ground cover.
Barren strawberry has three-parted leaves that are very like wild strawberry, a little shinier. The bright yellow flowers in mid spring resemble those of strawberry save for the colour. No berries, which is why it is called barren strawberry. Wild strawberry can make a fine ground cover in the right place, but its long overground runners make it difficult to contain. Barren strawberry spreads by short offsets so it will fill in its space nicely but not overrun walks and other garden spaces.
The photo shows barren strawberry growing in the wild. I tried to find a photo of barren strawberry in a garden situation but every one I have is of the European species. They are very similar in appearance. The flowers of the European are fuller, those of the native have slightly narrower petals.
Our most robustly evergreen fern, Christmas fern, associates well with evergreen sedges in shady gardens. Christmas fern (Polystichum acrostichoides) is a mid-sized fern with leathery foliage. If you can get it to grow in a dense mass it can be quite weed-suppressing (see photograph below). It is far more likely to reward you if it is grown in a rich, loose soil full of organic matter. Loose organic soil requires some work to establish and maintain in urban gardens, where heat and non-native earthworms breakdown organic matter with unnatural rapidity. Christmas fern will grow, and even thrive, in less accommodating soils but it will be slow to knit itself into a ground-covering mass. Look at the photo of wild Christmas fern growing in a woodlot – it has colonized an old, decaying log, thriving on the moisture and organic matter in the decaying wood, but it hasn’t moved into the surrounding soil. This picture was taken in mid-December. Christmas fern fronds used to be gathered for Christmas flower arrangements.
I promised to write about native ground covers this winter and I didn’t. The thing is, if I am going to write about low-growing evergreen native plants, I have to come out as a sedge-lover, a cariceophile (sp?), and I am not sure how that admission will be received.
I know, I hear you: sedges – grassy things that for some reason aren’t grasses, and have tiny flowers of some sort, and there seems to be an unnecessary lot them.